x,y,p,q=map(float,input().split())
print(((x-p)**2+(y-q)**2)**(1/2)) x,y,p,q=map(float,input().split()) x map(float,input().split()) map float input().split() ().split () input split y p q print(((x-p)**2+(y-q)**2)**(1/2)) print ((x-p)**2+(y-q)**2)**(1/2) (x-p)**2+(y-q)**2 (x-p)**2 x-p x p 2 (y-q)**2 y-q y q 2 1/2 1 2 x,y,p,q=map(float,input().split()) map(float,input().split()) x y,p,q=map(float,input().split()) map(float,input().split()) y p,q=map(float,input().split()) map(float,input().split()) p q=map(float,input().split()) map(float,input().split()) q
x,y,p,q=map(float,input().split())
print(((x-p)**2+(y-q)**2)**(1/2))
